Screen
The Screen junction type requires two connecting pipes. This junction type allows you to model the irrecoverable loss that occurs through a screen, mesh, or filter flow restriction. It also allows you to specify loss factors as a function of a flow parameter.
The Screen Properties Window follows the first of the two basic Properties Window formats, displaying the connecting pipes in a fixed format. The Screen junction does not have an explicit flow direction; it adopts a flow direction from the connecting pipes.
AFT Impulse provides four standard screen types for your use:
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Sharp-edged perforated plate
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Round-edged perforated plate
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Circular wire screen
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Silk thread screen
The loss factors for these screens are taken from handbook values. In addition to the standard screens that AFT Impulse provides, you may enter your own custom screen loss factor that is consistent with the application.
When you select Resistance Curve in the Loss Model section on the Loss Model tab, the Screen Properties window makes additional features available. Using these features, you can input pressure drops that vary with flow. To enter this information, you can specify polynomial constants, fit a curve to available data, or use interpolated x-y data.
